I'm trying to install the Ion-40 wired keypad with my existing i-on 40 main panel.

At the first mains switch on (with back-up battery and wired keypad connected) the manual says you should get option A and B on the keypad display. I get this on my display but the entire left side of the keypad buttons -including the A, B, C & D buttons (but excluding the big square button) do not do anything - ie when I press them, nothing happens. Pressing the others makes a beep and the keypad back lighting comes on for a few seconds.

The only other useful thing I can add is that the 'heart-beat' LED on the main panel is flashing and when I override the main alarm panel tamper switch before powering up, the light around the big square button on the keypad glows steady green rather then rapid flashing red it does when the tamper switch is activated. This suggests to me that the main panel and keypad are communicating happily... and, of course, working.

What am I doing wrong?

is this an additional keypad, do you have an existing keypad that functions?